Alguien me puede ayudar con este ejerciciox = 70 - y 2x + 3y = 180?

<img src="https://tex.z-dn.net/?f=%20%5Cleft%20%5C%7B%20%7Bx%3D70-y%5C%3A%281%29%7D%20%5Catop%20%7B2x%2B3y%3D180%5C%3A%282%29%7D%7D%20%5Cright.%20" />

<img src="https://tex.z-dn.net/?f=%5Cmathrm%7BSustituir%5C%3A%7Dx%3D70-y%5C%3Aen%5C%3A%282%29" />

<img src="https://tex.z-dn.net/?f=2%5Cleft%2870-y%5Cright%29%2B3y%3D180" />

<img src="https://tex.z-dn.net/?f=%5Cmathrm%7BPoner%5C%3Alos%5C%3Aparentesis%5C%3Autilizando%7D%3A%5Cquad%20%5C%3Aa%5Cleft%28b-c%5Cright%29%3Dab-ac" />

<img src="https://tex.z-dn.net/?f=140-2y%2B3y%3D180" />

<img src="https://tex.z-dn.net/?f=140%2By%3D180" />

<img src="https://tex.z-dn.net/?f=%5Cmathrm%7BRestar%5C%3A%7D140%5Cmathrm%7B%5C%3Ade%5C%3Aambos%5C%3Alados%7D%3A" />

<img src="https://tex.z-dn.net/?f=140%2By-140%3D180-140" />

y = 40

<img src="https://tex.z-dn.net/?f=%5Cmathrm%7BPara%5C%3A%7Dx%3D70-y" />

<img src="https://tex.z-dn.net/?f=%5Cmathrm%7BSustituir%5C%3A%7Dy%3D40%3A" />

[img = 10]

x = 30.